Four Palestinian children were killed while playing football yesterday as Israel hit back at the Gaza Strip with more than 10 air strikes, after Hamas militants escalated their rocket fire into southern Israel. The deaths follow that of a six-month-old Palestinian baby, who was killed the previous evening when Israel intensified its attack on Gaza after a 47-year-old Israeli man was killed by a Hamas-fired rocket.

The surge in fighting began after Israel killed five Hamas rocket launchers, prompting the group that rules Gaza to more than double its missile attacks into Israel's neighbouring towns.

While Wednesday's Israeli fatality was the first in nine months, rockets fall on the southern Israeli town of Sderot almost daily. In February alone, three Israeli children have been severely wounded, including one who lost his leg.

The Qassam rockets are notoriously inaccurate - Hamas launched 28 yesterday and only 10 landed in Israel - but there are growing fears that the militants are acquiring an arsenal with a longer range. Israel's police said five foreign-made rockets similar to the kind that Hizbullah fired from southern Lebanon into northern Israel, triggering the 2006 war, landed in Ashkelon, a city north of Sderot. One of the rockets pierced the roof of an apartment building, but no one was hurt.

Public pressure is mounting on Israel's government to stop the rockets, which have killed 13 since 2001. While visiting Sderot, the defence minister, Ehud Barak, said: "A solution to the Qassams will be found faster than what most people believe." But Israel refuses to talk to Hamas, because the Islamist group refuses to acknowledge the Jewish state's right to exist, will not renounce violence and refuses to adhere to previous peace agreements signed by Palestinian leaders.

Israel's attempts to thwart the militants with an eight month-long blockade on Gaza has driven the population into deep poverty, but it has failed to stop the militants' missile attacks. Pressure has been mounting for a harsher military response, yet the government is divided over how to improve the effectiveness of its military strikes. Some ministers are calling for a full scale invasion of Gaza.

"We must prepare for escalation. A large, significant and tangible ground operation. We won't flinch," Barak said in a closed meeting, according to the Associated Press. "Israel will reach those responsible, hit them in operations, and Hamas will pay the price for its activities."

But the interior minister, Meir Sheetrit, opposed a large scale ground operation, arguing that it would not put an end to the rocket fire. "This is the wrong approach and it won't lead us anywhere. We won't just go in and suddenly everything will be OK," he said, according to AP.

Instead, Sheetrit advocated an increase in the number of targeted killings of Hamas operatives. "We must not let anyone involved in the shooting stay alive."

Meanwhile, Egypt's foreign minister, Ahmed Aboul Gheit, met an Israeli delegation headed by the director general of the foreign ministry, Aaron Abramovich yesterday. They discussed Gaza and the need to improve the situation which has resulted in severe shortages of food, medication, building materials, fuel, electricity and other necessities.

By late yesterday afternoon, the two- day air strike on Gaza had killed 27 Palestinians, of which 12 were militants who died yesterday. Six of the dead were civilians, including the four boys, aged eight to 14, who were struck while playing football in the Jabaliya refugee camp in northern Gaza. Two were brothers and the other two were their cousins. Another 12-year-old boy was wounded and died later.

While Israel bombed northern and central Gaza, a gun battle broke out in the south, killing a girl. An Egyptian official and other witnesses said the 12-year-old was hit by a stray bullet, AP reported.